CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
NET REVENUES	$ 83,073		$ 77,040
COST OF REVENUES	37,096		37,176
GROSS PROFIT	45,977		39,864
OPERATING EXPENSES:
Research and development	13,490		12,272
Sales and marketing	12,110		10,781
General and administrative	7,646		7,734
Total operating expenses	33,246		30,787
INCOME FROM OPERATIONS	12,731		9,077
OTHER INCOME
Other income, net	257		217
Total other income	257		217
INCOME BEFORE PROVISION FOR (BENEFIT FROM) INCOME TAXES	12,988		9,294
PROVISION FOR (BENEFIT FROM) INCOME TAXES	625		(1,609)
NET INCOME	$ 12,363		$ 10,903
EARNINGS PER SHARE:
Basic	$ 0.41		$ 0.38
Diluted	$ 0.40	[1]	$ 0.37	[1]
SHARES USED IN PER SHARE CALCULATION:
Basic	30,239		28,754
Diluted	31,167	[1]	29,783	[1]

[1] The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has excluded the shares underlying the 2014 and 2013 awards in the 2014 and 2013 calculation, respectively, as those shares were not contingently issuable as of the end of the period.